#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
int main()
{
    // execl("/usr/bin/ls","/usr/bin/ls","-al",NULL);
    
    
    //execlp("ls","ls","-al",NULL);
    

    //binextern char** environ;
    // execle("/usr/bin/pwd","/usr/bin/pwd",NULL,environ);
   
    
    //char* argv[10]={NULL};
    //argv[0] = "/usr/bin/ls";
    //argv[1] = "-l";
    //argv[2] = NULL;
    //execv("/usr/bin/ls",argv);
    //printf("failed execv\n");
    
    
    //char* argv[10]={NULL};
    //argv[0]="ls";
    //argv[1]="-l";
    // argv[3]=NULL;
    //execvp("ls",argv);
    
    char* argv[10] = {NULL};
    argv[0] = "/usr/bin/pwd";
    argv[2] = NULL;
    extern char** environ;
    execve("usr/bin/pwd",argv,environ);
    printf("faild exec\n");

    return 0;
}
